PROJECT SUMMARY/ABSTRACT Nationally, over one-quarter of new HIV infections occur in adolescents and young adults, and the brunt of this youth epidemic is being borne by young Black men who have sex with men (YBMSM). HIV-positive YBMSM are additionally at high risk for suboptimal engagement in care, which has implications for individual morbidity and mortality as well as further transmission within the community. At the same time, prior work has demonstrated significant resilience and supportive social relationships among HIV-positive YBMSM. The unique strengths and vulnerabilities of YBMSM must be better understood in order to develop effective interventions that improve individual and public health outcomes. This proposal outlines an approach that seeks to integrate community-based participatory research with clinical research methods in order to understand the relationships between social network characteristics and engagement in HIV care among YBMSM. Specifically, we will focus on characterizing and augmenting YBMSM?s social capital, which we define as the sum of actual and potential resources contained in an individual?s social network. We will first conduct formative research with HIV-positive YBMSM as well as key informants from the community, to better understand the sources and characteristics of social capital among YBMSM. Next, with the guidance of a youth community advisory board, we will develop an intervention to augment social capital among HIV-positive YBMSM by engaging them in group projects aimed at community- oriented action. Finally, we will pilot test our intervention in a randomized controlled trial and assess its feasibility and acceptability as well as its impact on social capital and HIV care engagement outcomes. We are proposing a unique, strengths-based approach to augmenting HIV care engagement among YBMSM, and we believe that our utilization of community-based participatory methods will lead to the development of an intervention which is acceptable and sustainable in this population. Such novel strategies for improving engagement in care among YBMSM are critically needed to promote individual health and well-being, prevent secondary transmission, and decrease health disparities.